iwlwifi: pcie: allow the op_mode to freeze the stuck queue timer

This allows the op_mode to let the transport know that a
queue is currently frozen and that its timer should be
stopped.
When the queue is unfrozen, its timer should be set to
expire after the remainder of the timeout has elapsed.
This can be used when stations go to sleep. When a station
goes to sleep, the op_mode can freeze the timer so that the
queue will never be considered as stuck. When the station
wakes up, the queue will be unfrozen.
This is meant to avoid false positives that would happen if
a buggy station goes to sleep for a very long time. In case
we have a dedicated queue for this station (BA agreement)
and it goes to sleep for a very long time, the queue would
rightfully be stopped during all that time. In this case,
the stuck queue timer could fire and that would be a false
positive.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h
index 542a6810c81c..11ac5c58527f 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans.h
@@ -458,6 +458,8 @@ struct iwl_trans_txq_scd_cfg {
  * @txq_disable: de-configure a Tx queue to send AMPDUs
  *	Must be atomic
  * @wait_tx_queue_empty: wait until tx queues are empty. May sleep.
+ * @freeze_txq_timer: prevents the timer of the queue from firing until the
+ *	queue is set to awake. Must be atomic.
  * @dbgfs_register: add the dbgfs files under this directory. Files will be
  *	automatically deleted.
  * @write8: write a u8 to a register at offset ofs from the BAR
@@ -517,6 +519,8 @@ struct iwl_trans_ops {
 
 	int (*dbgfs_register)(struct iwl_trans *trans, struct dentry* dir);
 	int (*wait_tx_queue_empty)(struct iwl_trans *trans, u32 txq_bm);
+	void (*freeze_txq_timer)(struct iwl_trans *trans, unsigned long txqs,
+				 bool freeze);
 
 	void (*write8)(struct iwl_trans *trans, u32 ofs, u8 val);
 	void (*write32)(struct iwl_trans *trans, u32 ofs, u32 val);
@@ -873,6 +877,17 @@ void iwl_trans_ac_txq_enable(struct iwl_trans *trans, int queue, int fifo,
 	iwl_trans_txq_enable_cfg(trans, queue, 0, &cfg, queue_wdg_timeout);
 }
 
+static inline void iwl_trans_freeze_txq_timer(struct iwl_trans *trans,
+					      unsigned long txqs,
+					      bool freeze)
+{
+	if (unlikely(trans->state != IWL_TRANS_FW_ALIVE))
+		IWL_ERR(trans, "%s bad state = %d\n", __func__, trans->state);
+
+	if (trans->ops->freeze_txq_timer)
+		trans->ops->freeze_txq_timer(trans, txqs, freeze);
+}
+
 static inline int iwl_trans_wait_tx_queue_empty(struct iwl_trans *trans,
 						u32 txqs)
 {